The present invention relates generally to the processing of cacao beans, or cocoa beans as they are otherwise called. The first main step in such processing is the removal of the skins or shells, commonly referred to as "de-hulling". This is normally carried out by a process of mechanical abrasion and cracking, which assists in releasing the skins from the beans which are then subsequently separated out by a winnowing process. The mechanical abrasion and cracking stage, may be preceded by pre-roasting of the beans. This is intended to assist the subsequent mechanical treatment, but also makes it more critical in that it involves the risk of producing quantities of small particles and powder which are difficult to separate from the particles of shell. Moreover it imparts an unacceptable smoky taint to the nib or de-hulled bean and causes a loss of fat from the bean to the shell.
Another possible variation in the processing lies in the use of micro-waves for the pre-treatment of the beans. Although appearing promising, this is no quicker than any other form of pre-roasting, e.g. four to ten minutes, and has the disadvantage of roasting the whole bean from the inside out. This leads to considerable fat loss to the shell and difficulty in the subsequent processing of the beans.
With previous methods of processing a typical nib yield has been 81% of the raw bean weight and the highest yield obtainable has been of the order of 83%. Whatever the method of processing, a constant problem arises from the presence of rodent hairs and insect fragments adhering to the raw beans and which tend to find their way through the winnowing machine into the nibs, thus causing considerable difficulties of hygiene. Similar hygiene problems arise from the presence of moulds, yeasts and bacteria.